Method of manufacturing composite wood flooring

ABSTRACT

A fiber reinforced composite wood board is designed particularly for use in the flooring of truck trailers which experience adverse operating conditions such as from heavy loads of lift trucks on the top side and water spray during rainy periods on the bottom side. The composite wood board comprises an edge-glued laminated wood member composed of wood segments with end joints. The wood member is underlaid with a thin layer of fiber reinforced plastic. The top surface of the composite wood board is the same as that of the laminated wood. The fiber reinforced plastic underlay is composed of glass and/or carbon fibers embedded in a polymeric resin such as epoxy, phenolic, vinyl ester, polyester, polypropylene or polyamide resin. Further, the fiber reinforced plastic underlay is substantially bonded to the wood member with a reactive hotmelt adhesive. The fiber reinforced plastic provides high fatigue resistance to the composite wood board and prevents water leakage into the trailer through the end joints of the wood segments.

RELATED APPLICATION

[0001] This application is a continuation of copending application Ser.No. 09/356,856 filed Jul. 19, 1999 which is a continuation-in-part ofapplication Ser. No. 08/484,364 filed Jun. 7, 1995 and application Ser.No. 09/294,476 filed Apr. 20, 1999.

BACKGROUND OF THE INVENTION

[0002] This invention relates to an improved laminated wood flooring fortruck trailers and containers. Fiber reinforced polymer compositematerials are used in conjunction with edge-glued laminated wood membersto provide improved mechanical properties, moisture protection, fatigueresistance and light weight to the resulting composite boards for use inflooring of vehicular trailers.

[0003] Conventional wood flooring for over-the-road truck trailers andcontainers is normally manufactured with hardwoods such as oak, maple,birch, beech, etc. The green lumber used as a starting material in suchmanufacture is suitably dried in special drying chambers undercontrolled conditions. The dried lumber is then sawed into strips ofrectangular cross-section and defective portions are eliminated by crosscutting the strips. During the crosscutting process, “hooks” are formedat the ends of the lumber strips. The relatively defect-free lumberstrips are coated on their vertical sides or edges with an adhesive suchas urea-melamine formaldehyde or polyvinyl acetate. The uncurededge-glued lumber strips are then assembled on a conveyor by placingthem side to side and behind other strips, which were previouslyassembled. Applying heat and edge pressure to large sections of theassembled lumber strips cures the adhesive thus forming a unitary panel.During the assembly of the lumber strips, “hook joints” are formed ateach end of every lumber strip. These joints are simple mechanicalcouplings between the mating hook ends of opposing lumber strips withoutsignificant adhesive bonding at the joint itself. Often times, due toimperfect assembly, a readily visible gap is formed at the hook joints,which can be seen from the top and bottom surfaces of the finishedlaminated wood floor.

[0004] The cured laminated wood is cut to a desired length (up to about60 feet) and width (about 6 to 18 inches) to form boards. The boards arethen planed to a desired thickness and shiplaps and crusher beads aremachined on its sides. A shiplap is a rectangular projecting lip runningalong the length on each side of a floor board. The crusher bead is asmall semi-circular projection running along the length on each side ofa board and placed over or below a lip. When the floor boards areassembled in a trailer such that the side edges of corresponding boardsare squeezed together, the shiplaps of adjacent boards overlap to form aseam. The crusher beads provide spacing between adjacent boards and helpin preventing buckling of the boards due to expansion on absorption ofwater. A wood putty is applied at the hook joints on the top and bottomsurfaces of the boards to fill any resident gaps. Finally, the undersideof the floor boards is coated with a polymeric substance termed as“undercoating” to provide moisture protection. The finished floor boardsare assembled into a kit of about eight boards for installation intrailers. Normally, a kit consists of two boards with special shiplapsso that they will fit along the road and curb sides of a trailer. Theother boards may be identical in design and they are placed between theroad and curb side boards. In some trailers, a metallic component suchas a hat-channel may be placed between any two adjacent boards. Themetallic component becomes part of the floor area. The boards adjacentto the hat-channel have shiplaps designed to mate with the flanges ofthe metallic component. All the boards are supported by thin-walledcross-members of I, C or hat sections, each having an upper flange,which span the width of the trailer and are spaced along the length ofthe trailer. Each floor board is secured to the cross-members by screwsextending through the thickness of the board and the upper flanges ofthe cross-members.

[0005] Hardwood-based laminated wood flooring is popularly used in trucktrailers since it offers many advantages. The surface characteristics ofhardwoods such as high wear resistance and slip resistance are mostdesirable. The strength and stiffness of the flooring is important forefficient and safe transfer of the applied loads to the cross-members ofthe trailer. The shock resistance of wood is useful to withstand anysudden dropping of heavy cargo on the floor. Nail holding capability andability to absorb small amounts of water, oil or grease withoutsignificantly affecting slip resistance are yet additional favorableproperties of hardwood flooring.

[0006] Although the conventional wood flooring has many desirablefeatures, it also suffers from certain disadvantages. For example, waterfrom the roads is known to leak into trailers through the gaps of thehook joints that exist in the flooring. The reasons for the water leaksare believed to be the capillary action of the gaps and the tendency ofthe end grain of wood to absorb and store water. Although theundercoating is supposed to provide a barrier to the path of water, itmay not properly cover larger gaps thus exposing them to moisture.Wetting and drying cycles can degrade the undercoating leading to itscracking and peeling away from the wood. Bending of the floor betweentwo adjacent cross-members due to any applied load on the top of thefloor also has a tendency to open the hook joints and enlarge the gaps.

[0007] A lift truck is often used on the trailer floor to load andunload cargo. The dynamic action of a moving lift truck placing heavycargo on the trailer floor creates severe stress concentration in theflooring and some of the cross-members. A very large amount of theweight of the lift truck and that of the cargo is transferred to theflooring through the wheels of the front axle of the lift truck due tothe momentary raising of the rear axle when the lift truck isdynamically placing a heavy cargo on the floor. The effect of repeatedlift truck operation on the conventional wood floor causes considerablefatigue damage including: delamination of the edge glued lumber stripsnear the hook joints leading to the “pop-out” of the lumber strips;crack initiation and propagation in wood on the underside of the floordue to tensile stresses; and cracking of edge glue lines due toshearing, transverse bending and twisting of the floor. The combinationof moisture attack and fatigue damage to the wood floor affects itsperformance thus necessitating its repair or replacement. In some cases,catastrophic structural failure of the trailer floor system may occurleading to the unacceptable injury to working personnel and damage tomachinery.

[0008] To alleviate the above-mentioned problems, novel fiber reinforcedcomposite wood flooring was designed, tested and refined to be animprovement over conventional wood flooring. This new composite woodflooring consists of conventional laminated wood member with an underlayof fiber reinforced plastic (FRP) bonded to the wood member. The topsurface of the composite wood flooring is essentially the same as thatof the conventional wood flooring. Since the FRP is impervious to thepassage of water, it completely seals the bottom of the wood member andsolves the problem of leaky hook joints. The fiber reinforcementimproves the mechanical properties of the flooring and therefore thethickness of the laminated wood can be reduced. Thus, thinner andlighter composite wood flooring can be produced with equivalent strengthwhen compared to thicker conventional wood flooring. Since thereinforcement provides an excellent barrier to the “pop-out” of lumberstrips, the fatigue resistance of the composite wood flooring can beimproved over that of the conventional wood flooring.

[0009] Technologists are constantly trying to find ways to improve themechanical properties, reduce weight and improve moisture resistance ofwood flooring. Fouquet, U.S. Pat. No. 5,143,418 describes the use ofcomposite plywood panels as flooring in truck trailers. The plywood wascomposed of veneers of wood with a majority of the veneers oriented withthe wood grain along the longitudinal direction while the remainingveneers were oriented with the wood grain along the transversedirection. The top and bottom surfaces of the plywood panels wereoverlaid with resin impregnated cellulose sheets for providing moistureand slip resistance. Clearly, Fouquet has not considered a floor designinvolving the FRP to provide higher strength and moisture protection.

[0010] Another area of related art is the use of FRP to improve themechanical properties of structural wood members, such as beams, columnsand trusses. Theakston (Canadian Agricultural Engineering, January 1965,Pages 17-19) has discussed the use of glass fibers and epoxy resin toreinforce laminated timber beams and arches. Triantafillou and Deskovic(Journal of Structural Engineering, Vol. 118, No. 5, May 1992, Pages1270-1284) have published test results on the reinforcement ofstructural wood beams by adhesively bonding prestressed carbon fiberbased FRP panels using epoxy adhesive. Thus the concept of reinforcingstructural wood members (especially beams) with FRP has been known forseveral decades. Tingley, U.S. Pat. No. 5,362,545 describes the use of aresorcinol adhesive to bond certain special composite panels toglue-laminated wood beams (Glulams). The special composite panelscontaining aramid (Kevlar®) fiber reinforcement are abraded by sandingprior to bonding. The sanding process makes the panel “hair up” due toKevlar and helps to obtain improved bonding with wood. The Tingleypatent teaches the utility of Kevlar in FRP panels to improve the bondstrength of the FRP to wood while using a resorcinol adhesive.

[0011] The above-referenced patents and publications have not addressedthe construction and related benefits of reinforced laminated woodflooring for use in truck trailers. The advantages of reinforcing thebottom side and disadvantages of reinforcing the top side of thelaminated wood boards are not disclosed in these references. Thepublications do not discuss the remedies for the problems associatedwith the conventional wood flooring such as water leakage through thehook joints and fatigue damage due to lift truck traffic on the floor.There is no discussion in the publications regarding the type ofreinforcements and resins that are suited for the fabrication ofreinforced composite wood flooring. For example, the question of whetherfiber reinforcement along the width (transverse) direction of the flooris advantageous is not addressed in these publications. A reinforcedcomposite wood flooring construction such as that provided by thepresent invention which is suitable for lift truck movement and also forcarrying cargo in a trailer has never before been invented.

[0012] Methods of manufacturing the reinforced composite wood boards toconstruct the improved flooring have never been considered before. Themanufacturing process needs to be able to produce the composite woodboards at a fairly high speed to meet the demands of volume and costeffectiveness. The conventional laminated wood boards are typicallymanufactured at a rate of about 1500 to 2000 sq ft/hr using one set ofmachinery. To be competitive, composite wood boards need to be producedat a similar production rate. Since dissimilar materials with mismatchof physical properties are bonded together to manufacture composite woodboards, precaution has to be taken to ensure the flatness of the boardafter the bonding is completed. The adhesive used to bond the FRP andwood member should not excessively leak under the bonding pressure.Squeeze-out of adhesive can contaminate the surfaces of the substratesrequiring additional clean-up operation. The bond between the FRP andwood member needs to be strong enough to resist the stress concentrationaround the hook joints and also be fatigue and moisture resistant.

SUMMARY OF THE INVENTION

[0013] Unlike the FRP-wood structural beams, the reinforced compositewood flooring of the present invention is designed to provide severaldesirable features. The composite wood floor consists of a plurality ofcomposite wood boards. The top side of each of the composite wood boardsis composed of a laminated wood member with a construction similar tothat of conventional wood boards of trailer flooring. This provides ahigh coefficient of friction and slip resistance, thereby facilitatingthe safe movement of man and machine. The surface of wood can alsoabsorb small amounts of water that may spill over it. Any oil or greasethat spills on the wood surface can be wiped off and the left over slickis absorbed by the pores of wood as in the conventional wood flooring.On the contrary, even an extremely thin coating of oil on FRP can renderit dangerously slippery and therefore, FRP is not laid on the top sideof the composite wood board. An FRP is bonded to the bottom side of thelaminated wood member to provide protection to wood from the outsideenvironment. The FRP underlay of the composite wood flooring eliminatesthe need for a polymeric undercoating and for puttying of hook jointsthat is required in the conventional wood flooring. In fact, the needfor hook joints themselves can be eliminated; that is, the lumber stripscan be joined at butt ends thereof or by finger or lap and gap joints.However, the use of hook joints is preferred. The gaps in the hookjoints are completely sealed by the FRP, thus preventing water leakageinto the trailer through the flooring.

[0014] Preferably, the FRP is fabricated with glass fibers and an epoxyresin. Other reinforcements such as carbon and aramid fibers and otherthermosetting resins such as vinyl ester, polyester, phenolic resins andthe like and other thermoplastic resins such as polypropylene andpolyamide resins and the like can also be used to fabricate the FRP. Theglass fiber reinforcement provides an economical means of increasing thestrength of the flooring in the longitudinal and transverse directions.The epoxy resin binds the glass fibers together and protects the fibersfrom adverse environment. The reinforcing fibers resist the pop-out ofthe lumber strips of composite wood floor in trailers when subjected tothe fatigue loads of heavy lift trucks. The transverse reinforcementresists the splitting of the FRP and delamination of edge-glue lines inlaminated wood during the application of shearing, twisting andtransverse bending loads on the floor. Thus, our design of the compositewood floor provides improvements in the prevention of moisture leakagethrough hook joints, maintains the desirable surface characteristics ofthe wood on the top surface and also provides significant improvementsin fatigue resistance at lower weight.

[0015] The manufacture of the composite wood boards can be accomplishedby means of a suitable process wherein the fiber reinforced plastic isbonded to the surface of laminated wood member. In a wet process, thefiber reinforcement is saturated with a reactive liquid polymeric resin.The resin-wetted reinforcement is placed in contact with the surface ofthe laminated wood and the resin is cured under heat and pressure. Ahotpress can be used to apply heat and pressure on the resin-wettedreinforcement while it is still in contact with the laminated wood. Thecomposite wood board can also be manufactured by adapting the pultrusionprocess, which normally involves the pulling of resin-wettedreinforcement through a stationary heated die where the FRP is shapedand the resin is cured. The laminated wood and the resin-wettedreinforcement can be pulled together through a heated die to producecomposite wood board. In the wet processes as described above, it ispossible to use the same resin to bind the fibers together or form thematrix of the FRP and also to bond the fibers to the wood member.

[0016] In the above-mentioned processes, which uses liquid resinsseveral practical problems are encountered. The simultaneous applicationof heat and pressure to consolidate and cure the resin-wettedreinforcement leads to squeeze-out of the resin. The applied temperaturereduces the viscosity of the resin further compounding the squeeze-outof resin. The squeeze-out of the resin can occur at the sides of thelayer of the wetted reinforcement or through the hook-joints of the woodmember, since gaps are present at many of these joints. The compositeboard formed with the squeeze-out of resin needs a significant degree ofsubsequent machining to provide the required dimensions and shape ofshiplaps along the longitudinal edges. Further, the FRP layer, which isformed under heat and bonded to a wood member under heat tends to shrinkas it cools down. Due to unsymmetrical construction of the compositeboard with FRP bonded to one surface of a wood member and difference inthe thermal expansion coefficients of wood and FRP, the composite woodboard formed by heating the resin wetted reinforcements tends to warp oncooling. Typically, the composite board develops a bowed shape along thelength of the board. For truck-trailers, the floor boards need to besubstantially flat for easy installation and use.

[0017] In order to overcome the problems of squeeze-out of the resin andwarping of the boards due to heating of the FRP for curing the resin, itis better to adhesively bond a prefabricated FRP sheet to the woodmember with minimal application of heat to the FRP and wood. A suitableprefabricated FRP sheet can be bonded to laminated wood usingthermosetting or thermoplastic adhesives. Thermosetting adhesivesinclude epoxy, polyurethane, phenol-resorcinol formaldehyde,urea-melamine formaldehyde, etc. Thermoplastic adhesives includehotmelts such as ethylene vinyl acetate polymers (EVA), polyamide, etc.Experiments have shown that thermosetting liquid adhesives can be usedto fabricate composite wood floor. However, squeeze-out of the adhesivethrough the hook joints of the wood member continues to be a problemwhen heat and pressure are applied. Further, application of excessiveamount of heat through the FRP to quickly cure the adhesive leads towarping of the board as mentioned before. Even though the use ofthermoplastic hotmelt adhesives such as EVA in bulk form or filmseliminate squeeze-out, they do not lead to sufficient bond strength toresist the pop-out of the lumber strips at the hook joints.Thermoplastic hotmelt adhesives with relatively high strength canprovide the required performance. After several experiments andextensive testing, reactive hotmelt adhesive has been determined to bethe best choice to bond prefabricated FRP to wood members to manufacturecomposite wood boards. This method offers high speed of production withminimal application of heat and good bonding of the FRP to wood membersto resist the opening of the hook joints under load along with little orno squeeze-out of the adhesive during production.

[0018] Reactive hotmelt adhesives behave like a typical non-reactivehotmelt adhesive during processing or bonding, but subsequently undergochemical reactions with moisture to transform into a cross-linkedthermosetting adhesive. By means of cross-linking, the molecular weightof the adhesive increases thus providing higher bond strength andhygrothermal resistance. Reactive hotmelt adhesives are solvent freesolids at room temperature. They are melted by heating and then appliedon the bondable surface of the substrates by means a roller coater.Typically, only one substrate needs to be coated in order to bond toanother uncoated substrate. However, both substrates may be coated, ifrequired. After coating one or both substrates with the reactive hotmeltadhesive, the substrates are joined and pressed together by a platenpress or by means of rollers. The joined and pressed parts are allowedto cure for 1 to 7 days before use.

[0019] Reactive hotmelt adhesives are highly suited to the bonding ofprefabricated FRP sheets to wood members for manufacturing compositeflooring for trailers. The adhesive is the only component that needs tobe heated to about 200° F. to 350° F. for the bonding process. Thebonding surfaces of the wood board and FRP need to be warmed up to about60° F. to 200° F., if required. Since the FRP is not substantiallyheated for curing its polymer, the quantity of heat required for thebonding process is minimized. This leads to the production ofsubstantially flat boards with little or no warping after bonding. Sincethe reactive hotmelt is used and applied as a traditional hotmelt, itleads to high manufacturing speed. The cross-linking of the reactivehotmelt provides higher hygrothermal resistance and therefore, thecomposite floor can perform well under the harsh environment of theroadways. Since the reactive hotmelt has a fairly high strain tofailure, it develops high peel strength, which is particularly importantto reinforcing the hook joints of the wood member. When a typicalbrittle adhesive with a low strain to failure is used in thisapplication, it leads to debonding of the FRP from the wood board at theregions of high stress surrounding the hook joints under an applied loadon the floor board. These debonds can grow due to fatigue loads of lifttruck on the floor of a trailer, leading to large-scale failure.However, the reactive hotmelt has been shown to work very well underfatigue loading in our testing and experiments. Due to a number ofadvantages as stated above, both in processing and performance ofcomposite wood flooring, reactive hotmelt has been determined to be thepreferred adhesive for this application. The use of a reactive hotmeltfor bonding prefabricated FRP to wood members with hook joints, in orderto improve its strength, stiffness, fatigue resistance and waterproofing ability for use in vehicular trailer flooring has never beenpublished before. Any suitable reactive hotmelt adhesive may be employedin the process of this invention.

[0020] The FRP sheet can be produced by pultrusion and continuouslamination processes. In the pultrusion process, the resin-wettedreinforcements are pulled under tension through a stationary heated diewhere the FRP is shaped and cured. In continuous lamination process,reinforcements are wetted with a polymeric resin. The wettedreinforcements are aligned in a die and then cured in an oven. Typicalreinforcements used for the pultrusion process include continuousrovings, stitched, woven or knitted fabrics and continuous strand mats.In the continuous lamination process, chopped strands and chopped strandmats can be used in addition to the above-mentioned reinforcements.Preferred reinforcements for our prefabricated FRP are continuousrovings in the longitudinal direction of the FRP sheet and fabrics fortransverse reinforcement. The fabrics may also be designed to providebidirectional structural properties.

[0021] The FRP is sanded or abraded on at least one major surface inorder to provide a clean surface and uniform thickness to the FRP sheetfor bonding to the wood member. The wood member is prepared by planingthe major surfaces. Since planing produces a lesser degree of flatnessthan sanding, the planed board can be sanded at least on one surface towhich the FRP is eventually bonded. The planed or sanded surface of thewood board is coated with a reactive hotmelt. Preferably, both the FRPand wood member are coated on their major surfaces with the adhesive.This provides improved bonds between the FRP and wood. Alternatively,only one of the two substrates may be coated with the reactive hotmelt.By coating on both surfaces, the chances of skipping any low spots onthe FRP or wood would not be a significant problem during production.After the substrates are coated, they are joined together so that theedges of the FRP are laid within a predetermined distance from the edgesof the wood member. The joined parts are pressed together by a series ofrollers. Simultaneously, the parts are cooled by means of forced air.The process of coating the substrates and joining them is conducted in acontinuous fashion to obtain a relatively high manufacturing speed.

[0022] The present invention provides a novel process for manufacturingcomposite wood flooring for use in truck trailers that is subjected tolift truck loads on the top side and water spray on the bottom side. Thecomposite wood flooring consists of a plurality of composite boards eachof which is composed of a wood member with a fiber reinforced polymeradhesively bonded to the bottom side of the wood member using reactivehotmelt adhesive. Since the top side of the composite wood flooring iscomposed of wood, many desirable features of wood such as slipresistance, abrasion resistance and nailing capability are preserved.The underlayer of the composite wood flooring provides improved fatiguestrength and moisture protection to wood. Since the mechanicalproperties of the reinforced composite wood flooring are superior tothose of the conventional wood flooring, the thickness of the compositewood floor can be reduced leading to lower floor weight in a trailer.Alternatively, the load carrying capacity of the trailer can beincreased with a suitable composite floor while having little or noincrease in the weight of the trailer.

[0023] The process of this invention particularly comprises a process ofmanufacturing a composite wood board for use with a plurality of suchcomposite wood boards in a floor system of a vehicular trailer orcontainer, wherein each composite board comprises a unitary wood memberwith an exposed wood top surface and a bottom surface substantiallybonded to a continuous planar layer of fiber reinforced polymerrendering the bottom surface substantially non-exposed, the processcomprising the steps of:

[0024] providing the wood member as a side-to-side or edge bondedplurality of wood segments in an approximately planar arrangement with asubstantial majority of the wood segments having shaped couplingportions at ends thereof, which ends are engaged to form severalrandomly placed end joints in the wood member;

[0025] machining the bonded wood segments to produce a planar woodmember with two opposing major surfaces and first and second sidesurfaces, said wood member having a length, width, thickness andlongitudinal and transverse axes;

[0026] providing a planar layer of fiber reinforced polymer having twomajor surfaces and a length, width, thickness and longitudinal andlateral axes, said planar layer of fiber reinforced polymer comprising athermosetting or a thermoplastic polymer and reinforcing fibers, with atleast about 70% of the fibers of said fiber reinforced polymer extendingin a direction substantially parallel to the longitudinal axis of theplanar layer of fiber reinforced polymer;

[0027] altering at least one major surface of the planar layer of fiberreinforced polymer by sanding or abrasion to provide a uniform thicknessand clean bonding surface to the planar layer of fiber reinforcedpolymer;

[0028] substantially aligning the longitudinal axis of the planar layerof fiber reinforced polymer with the longitudinal axis of the woodmember and substantially continuously coating one or both of themachined major surface of the wood member and the altered major surfaceof the planar layer of fiber reinforced polymer with a reactive hotmeltadhesive, followed by joining of the planar layer of fiber reinforcedpolymer to the wood member and pressing of the joined surfaces together,causing substantially no squeeze-out of the adhesive through the endjoints of the wood segments and causing substantially no heat relateddistortion of the wood member; and

[0029] curing the adhesive under ambient conditions to bond the planarlayer of fiber reinforced polymer to the wood member to produce acomposite wood board;

[0030] whereby said substantially continuous planar layer of the fiberreinforced polymer bonded to the bottom surface of the wood member ofthe composite board resists pop-out of the wood segments at the couplingportions at the ends of the wood segments and improves one or more ofthe flexural modulus, strength and load carrying capacity of thecomposite wood board.

BRIEF DESCRIPTION OF THE DRAWINGS

[0031]FIG. 1 is a perspective view of a van trailer showing thecomposite wood flooring installed on cross-members with an I-section.

[0032]FIG. 2 is a longitudinal sectional view of a composite wood floorboard fastened to cross-members of an I-section.

[0033]FIG. 3 is the end view of the shiplap assembly of two adjacentcomposite wood floor boards on an I-beam cross-member.

[0034]FIG. 4a is a perspective view of laminated wood with severalrandomly arranged hook joints.

[0035]FIG. 4b is a perspective view of two opposing hooked ends oflumber strips.

[0036]FIG. 4c is a perspective view of a perfect hook joint with littleor no gap.

[0037]FIG. 4d is a perspective view of an imperfect hook joint with asignificant gap.

[0038]FIG. 5 is a perspective view of a conventional laminated woodfloor board with shiplaps and crusher beads.

[0039]FIG. 6 is a perspective view of a reinforced composite wood floorboard with shiplaps and crusher beads.

[0040]FIG. 7 is a sectional view of a reinforced composite wood floorboard of a first embodiment of the invention.

[0041]FIG. 8 is a sectional view of a reinforced composite wood floorboard of a second embodiment of the invention.

[0042]FIG. 9a is a sectional view of a lap joint between two lumberstrips.

[0043]FIG. 9b is a sectional view of a finger-joint between two lumberstrips.

[0044]FIG. 9c is a sectional view of a butt joint between two lumberstrips.

[0045]FIG. 9d is a sectional view of a scarf joint between two lumberstrips.

[0046]FIG. 10a is a sectional view of a reinforced composite wood floorboard with two shiplap edges having bottom cuts.

[0047]FIG. 10b is a sectional view of a reinforced composite wood floorboard with a shiplap edge having a shallow bottom cut.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0048] The reinforced composite wood flooring of the present inventionis an improvement over conventional wood flooring of truck trailers inthat it provides both moisture proofing and reinforcement to suchflooring. In order to understand the benefits provided by the compositewood flooring, it is first necessary to understand the construction ofconventional laminated wood flooring.

[0049] Conventional wood flooring 11 for over-the-road truck trailers 12such as that shown in FIG. 1 is normally manufactured with hardwoodssuch as ash, aspen, elm, yellow-poplar, and preferably oak, maple,birch, beech and the like, although softwoods such as Douglas fir andspruce could be employed. The green lumber used as a starting materialin such manufacture is suitably dried in special drying chambers undercontrolled conditions. The dried lumber is then sawed into strips 21 ofrectangular cross-section and defective portions are eliminated by crosscutting the strips. During the cross-cutting process, “hooks” 24 areformed at the ends of the lumber strips (see FIG. 4b). The relativelydefect-free lumber strips are coated on their vertical sides or edges 25with an adhesive such as urea-melamine formaldehyde or polyvinylacetate. The uncured edge-glued lumber strips are then assembled on aconveyor by placing them side to side and behind other strips which werepreviously assembled forming glue lines 22 between adjacent strips 21.The adhesive is cured by applying heat and edge pressure to largesections of the assembled lumber strips thus forming a unitary panel oflaminated wood 20 such as that shown in FIG. 4a. During the assembly ofthe lumber strips, “hook joints” 23 are formed at each end of everystrip (see FIG. 4c). These joints are simple mechanical couplings withno significant adhesive bonding. Often times, due to imperfect assembly,a readily visible gap 26 is formed at the hook joints which can be seenfrom the top and bottom surfaces of the completed laminated wood floor(see FIG. 4d).

[0050] The cured laminated wood 20 is cut to a desired length (up toabout 60 feet) and width (about 6 to 18 inches) and then machined toform several laminated wood boards 16 (see FIG. 5). Each laminated woodboard 16 is planed to a desired thickness and shiplaps 18 and crusherbeads 19 are machined on its sides. A shiplap 18 is a rectangularprojecting lip running along the length on each side of a floor board.The crusher bead 19 is a small semi-circular projection running alongthe length on each side of a board and placed above or below a shiplap18. When the floor boards are assembled in a trailer such that the sideedges of corresponding boards are squeezed together, the shiplaps 18 ofadjacent boards overlap to form a seam. The crusher bead 19 providesspacing between adjacent boards and help in preventing buckling of theboards when they expand on absorbing moisture. A wood putty is appliedat the hook joints 23 on the top and bottom surfaces of the boards tofill any resident gaps. Finally, the underside of the floor boards arecoated with a polymeric substance termed as “undercoating” 27 (FIG. 5)to provide moisture protection. The finished floor boards are assembledinto a kit of about eight boards for installation in trailers. Normally,a kit consists of two boards with special shiplaps so that they will fitalong the road and curb sides 15, which are usually metallic componentsof the trailer 12. The other boards may be identical in design and theyare placed between the road and curb side boards. In some trailers, ametallic component such as a hat-channel may be placed between any twoadjacent boards. The metallic component becomes part of the floor area.The boards adjacent to the hat-channel have side edge profiles designedto mate with the flanges of the hat-channel. All the boards aresupported by thin-walled cross-members 14 of I, C or hat sections, eachhaving an upper flange, which span the width of the trailer and arespaced along the length of the trailer. Each floor board is secured tothe cross-members by screws 13 extending through the thickness of theboard and the flanges of the cross-members (See FIGS. 1-3).

[0051] The reinforced composite wood floor board 28 improves the abovedescribed construction of conventional wood floor board 16 byreinforcing and moisture proofing a laminated wood member 16 with alayer of fiber reinforced plastic (FRP) 17 (as representatively shown inFIG. 6). Two basic designs of the composite wood floor board 28 of theinvention with laminated wood member 16 on top and FRP 17 on the bottomare presented below. These designs differ from one another in the widthof the FRP as related to the face width of the wood member.

[0052] As shown in FIG. 7, the reinforced composite wood floor board 28consists of a laminated wood member 16 with an underlayer of FRP 17. Theshiplaps 18 and crusher beads 19 are incorporated on the sides of thereinforced composite wood floor board 28 similarly to those in aconventional laminated wood floor board (FIG. 5). The finished width ofthe FRP 17 is nearly equal to the face width of the wood member 16.During manufacturing, the starting width of the FRP is selected to beequal or slightly wider than the face width of the board. After bondingthe FRP to the board, the corners are machined so that the FRP does notoverhang the face width of the board.

[0053] The embodiment of FIG. 8 differs slightly from that of FIG. 7. Inthis case, the FRP 17 has a narrower width than the face width of thewood member 16. At each of the lateral sides of the board, the edge ofthe FRP is at least {fraction (1/64)}″ inside the edge of the woodmember. By bonding the FRP to the wood member at the correct locationrelative to the edges of the board, final machining of the lateral sidesof the composite floor board is avoided.

[0054] A laminated wood member 16 with shiplaps 18 and crusher beads 19is fabricated by the process set forth above for producing conventionallaminated wood floor boards. However, the wood member is not coated withan undercoating and the hook joints are not coated with a wood putty. Ifrequired, each hook joint at the ends of the lumber strips issubstituted with a lap joint 29 or a finger joint 30 or a butt joint 31or a scarf joint 32 as illustrated in FIGS. 9a to 9 d. In addition tousing a wood member with edge profiles to produce a composite board asshown in FIG. 6, other types of profiles are used to produce compositeboards as shown in FIGS. 10a and 10 b.

[0055] The FRP is fabricated with continuous fibers in the form ofcontinuous rovings and fabrics. About 70% to about 100% of the fiberreinforcement are aligned along the longitudinal direction while theremaining fibers are aligned along the lateral direction of the FRP. Thereinforcing fibers are glass, carbon or aramid fibers or mixturesthereof. Glass fiber is more economical than carbon and aramid fibers,but provides lower weight savings and flexural modulus than the otherfibers. For higher performance, carbon fiber is better suited toreinforce wood. Mixtures of glass and carbon fibers can also be used toimprove performance at moderate costs.

[0056] Epoxy resin is the preferred matrix for the fabrication of theFRP. Other thermoset and thermoplastic polymers such as vinyl ester,phenolic, polyester, polypropylene and polyamide can be used tofabricate the FRP. The method of fabrication of the FRP is dictated bythe type of polymer selected. Conventional pultrusion and continuouslamination processes are better suited for thermosetting resins.Typically, in these processes the reinforcing fibers are placed undertension and wetted with a reactive liquid resin, which is subsequentlycured around the fibers. To fabricate the FRP with a thermoplasticpolymer, the fibers are coated with the polymer and then the coatedfibers are consolidated under heat and pressure followed by cooling.Alternatively, co-mingled fibers of reinforcement and thermoplasticpolymer can be used to form the FRP. Irrespective of the fabricationprocess of the FRP, the FRP for composite wood flooring is preferablydesigned to have 70% to 100% of the continuous fibers aligned along thelongitudinal direction while the remaining fibers are aligned along thelateral direction of the FRP. The FRP sheet is preferably sanded orabraded on at least one side to render it flat and clean for bonding tothe wood member.

[0057] The laminated wood member with shiplaps and other edge details issanded or abraded on one side to develop a flatter surface than thatprovided by planing. Alternatively, a knife-planed surface of the woodmember can be used for bonding to the FRP. A reactive hotmelt adhesiveis coated on the sanded or planed surface of the board. Preferably, thesanded surface of the FRP is also coated with the reactive hotmelt.Commercially available hotmelt roller coaters are used to coat thesubstrates with the reactive hotmelt. Typical weight of coating on anyone substrate is about 5 to 20 gms/sq ft. The reactive hotmelt isapplied on the substrates in a molten state at a temperature generallyin the range of about 200° F. to 350° F.

[0058] Prior to bonding, the edges of the FRP are aligned with respectto the edges of the wood member. To manufacture a composite floor boardof Embodiment I, the width of the FRP is selected to be equal or widerthan the face width of the wood member. After bonding the FRP to thewood member, the FRP is either in line with or overhanging the edges ofthe wood member. In case of an overhanging FRP on the wood member, asecondary machining operation is employed to trim the FRP and wood.Since glass and carbon fibers are hard to machine than wood, a softerfiber such as polyester or cellulose is employed at the edges of the FRPduring its fabrication. To manufacture a composite floor board ofEmbodiment II, the width of the FRP is selected to be at least {fraction(1/16)}″ less than the face width of the wood member. The edges of theFRP are aligned with respect to the edges of the wood member such thatthere is no overhang of the FRP over the edges of the wood member.

[0059] The coated surface of the FRP is mated with the coated surface ofthe wood member while maintaining proper alignment of the edges of theboard and FRP. The joining of the FRP and wood member is done while thereactive hotmelt coating is in a tacky state. In case of a short opentime of the reactive hotmelt, to maintain the tacky state of thecoating, radiant heat is applied on the bonding surface of the FRP andwood member before or after the coating step. After the joining of theFRP and wood board, a series of rollers are used to apply pressure onthe substrates. Cooled air is blown over the substrates while pressureis applied to remove residual heat of the substrates and develop greenstrength of the bond. Quick development of green strength helps to holdthe FRP flat against the wood board and prevents debonding at the edges.

[0060] To manufacture the composite floor boards in a continuousfashion, a series of wood members of desired length and edge profilesare run one behind the other. The FRP is drawn from a roll of materialand continuously joined to the boards as the boards pass below the roll.After joining the FRP and wood members, the FRP is cut between the endsof two boards next to each other. The cutting of the FRP is done bymeans of an automatic cut-off saw without stopping the flow of theboards.

[0061] A 10 foot long composite wood floor kit consisting of eightcomposite boards was fabricated by bonding a glass/epoxy FRP to each ofthe eight laminated wood members using commercially availablepolyurethane reactive hotmelt, namely PUR-FECT LOK 34-9028 of NationalStarch and Chemical Company. The laminated wood was made of red andwhite oak strips which were edge-glued using urea-melamine formaldehydeadhesive. The fiber reinforcement of the FRP was composed of about 50oz/sq yd of continuous glass rovings in the longitudinal direction ofthe FRP. A fabric weighing about 4 oz/sq yd of glass fibers oriented inthe weft direction was used for transverse reinforcement. Wood membershaving a rectangular cross-section and without any shiplaps were used.The planed surface of the wood members and the sanded surface of the FRPsheets were coated with a reactive hotmelt. Upon joining and pressing ofthe substrates with rollers, the composite boards were allowed to cureat ambient conditions for five days. The boards were then machined toprovide the required shiplap profiles and crusher beads at thelongitudinal edges. The finished thickness of the reinforced compositewood floor was about 1.125 inches.

[0062] Eight composite floor boards were installed in a partial sectionof a trailer. The floor was supported by several I-beam cross-membersrunning along the full width of the trailer and regularly spaced at 12inches along the length of the trailer section. The cross-members with asection of 4 inches by 2.25 inches were made of steel with a yieldstrength of 80 ksi and weighing about 3.2 lbs/foot. Each floor board wassecured to each cross-member in the test section by three screws runningthrough the thickness of the boards and the top flange of thecross-member. A lift truck load simulator with two loading wheels wasstationed on the floor. The simulator was loaded with dead weights sothat a force of about 17,000 lbs could be applied on the floor throughthe loading wheels. The loading wheels were stationed on the third andsixth boards in the eight board configuration of the floor. To subjectthe floor to fatigue loading, the simulator was moved back and forth onthe floor. The simulator was allowed to complete 5,000 fatigue loadingcycles, wherein during each cycle the simulator moved forward in onedirection and then returned back to its starting line on the floor. Atthe end of 5,000 fatigue loading cycles, the reinforced composite floorexperienced little or no significant damage. The loading wheels wererepositioned on the first and fourth board and the fatigue test wasredone for another 5000 cycles. Since the damage to the composite floorboards was not significant, the fatigue test was continued at 20,000 lbsof loading on the same set of floor boards. The loading wheels werepositioned in two different locations as described above and anadditional 10,000 fatigue load cycles were applied. There was nocatastrophic damage to the floor boards and cross-members at any timeduring the test.

[0063] A conventional hardwood floor with a nominal thickness of 1.38″supported by standard cross-members at 12″ spacing is rated for 17,000lbs by the trailer industry. During fatigue testing, the conventionalhardwood floor typically undergoes cracking of some wood segments andopening of some hook joints at the bottom side of the floor. Themechanical properties of conventional hardwood flooring show a largevariation due to the random location of joints and variation ofproperties of the wood segments.

[0064] Compared to the conventional floor boards, the composite floorboards show superior performance with little or no opening of the jointsof the wood segments at the bottom side of the floor. The compositefloor boards show significantly lower variation of mechanical propertiesdue to the strengthening of the hook joints and better distribution ofload to the tensile bottom side of the floor. The thinner compositefloor of this experiment weighed about 4.8 lbs/sq ft, while the thickerconventional oak floor weighed about 5.4 lbs/sq ft. Thus, the compositefloor provides weight saving over the conventional hardwood floor whileproviding similar load capacity. By using carbon fibers or mixtures ofcarbon and glass fibers in a continuous roving form along thelongitudinal direction of the FRP, additional weight saving and evenhigher performance can be obtained.

[0065] Since the underside of the trailer flooring is subjected to waterspray in service, the environmental durability and aged properties ofthe floor is of importance to the long term performance of the floor. Todetermine the weathering characteristics of the floor boards thefollowing accelerated environmental test was conducted. Samples ofcomposite floor boards with a thickness of 1″ and conventional laminatedoak floor boards with a thickness of 1.31″ were tested. The sampleboards with a length of about three feet and width of about 12″ werefastened with screws to steel frames built with cross-members used intrailers to support the floor. The attachment of the boards to framessimulated a section of a single floor board of a trailer. The boards,which were attached to the frames were degraded by immersing them inwater for seven days and then drying them in a kiln at about 140° F. to160° F. for two days. The soaking and drying cycle was repeated oncemore. Finally, the boards were removed from the frames and subjected tobend test to determine the loss of ultimate failure load. It was foundthat the conventional oak floor suffered a loss of ultimate failure loadfrom 5200 lbs for the virgin boards to 3980 lbs for the degraded boards.On the other hand, the composite floor boards fabricated withglass/epoxy FRP and reactive hotmelt adhesive suffered a loss ofultimate failure load from 5920 lbs for the virgin boards to 4690 lbsfor the degraded boards. Further, conventional wood floor boards failedin a relatively brittle mode. The composite wood floor boards failed ina ductile fashion with little or no debonding of the FRP and withoutopening of the hook joints at the bottom side. The ductile failure modeand integrity of the composite boards provides higher performance totrailer floor.

[0066] With the foregoing description of the invention, those skilled inthe art will appreciate that modifications may be made to the inventionwithout departing from the spirit thereof. Therefore, it is not intendedthat the scope of the invention be limited to the specific embodimentsillustrated and described.

I claim:
 1. A process of manufacturing a composite wood board for usewith a plurality of such composite wood boards in a flooring system of avehicular trailer or container, wherein each composite board comprises aunitary wood member of a plurality of wood segments and having a topsurface and a bottom surface, the process comprising the steps of:providing the wood member with two opposing major surfaces; providing awater impervious layer; altering at least one major surface of the waterimpervious layer to provide a bonding surface to the water imperviouslayer; substantially aligning a longitudinal axis of the waterimpervious layer with a longitudinal axis of the wood member andsubstantially continuously coating at least one or both of a majorsurface of the wood member and the at least one altered major surface ofthe water impervious layer with a reactive hotmelt adhesive, followed byjoining of the water impervious layer to the wood member and pressing ofthe joined surfaces together, and curing the adhesive under ambientconditions to bond the water impervious layer to the wood member toproduce a composite wood board.
 2. The process according to claim 1wherein the impervious layer comprises a planar layer of fiberreinforced polymer comprising a thermosetting or a thermoplastic polymerand reinforcing fibers.
 3. The process according to claim 2 wherein atleast 70% of the fibers of the fiber reinforced polymer extend in adirection substantially parallel to a longitudinal axis of the layer offiber reinforced polymer.
 4. The process of claim 1 , wherein saidaltering is by sanding or abrasion.
 5. The process of claim 2 , whereinsaid planar layer of fiber reinforced polymer comprises continuousrovings of glass or carbon or aramid fibers or mixtures thereofimpregnated by a polymeric resin.
 6. The process of claim 2 , whereinsaid wood is a hardwood selected from the group consisting of ash,yellow-poplar, elm, oak, maple, birch and beech.
 7. The process of claim2 , wherein the reactive hotmelt adhesive is coated on both the majorsurface of the wood member and the altered major surface of the planarlayer of fiber reinforced polymer.
 8. The process of claim 2 , whereinsaid planar layer of fiber reinforced polymer comprises rovings ofcontinuous fibers impregnated by a polymeric resin.
 9. The process ofclaim 2 , wherein said planar layer of fiber reinforced polymercomprises one or more fabrics of reinforcing fibers, which fabric isselected from the group consisting of woven rovings, stitched fabrics,and knitted fabrics.
 10. The process of claim 2 , wherein the planarlayer of fiber reinforced polymer comprises a combination of continuousrovings and one or more fabrics of reinforcing fibers impregnated by apolymeric resin.
 11. The process of claim 2 , wherein said planar layerof fiber reinforced polymer comprises one or more strand mat impregnatedby a polymeric resin.
 12. The process of claim 2 , wherein said planarlayer of fiber reinforced polymer comprises glass or carbon or aramidfibers or mixtures thereof.
 13. The process of claim 2 , wherein thepolymer of the planar layer of fiber reinforced polymer is selected frompolymers of the group consisting of vinyl ester, polyester, epoxy,phenolic, polypropylene, and polyamide polymers.
 14. The process ofclaim 1 , wherein a major surface of the wood member is knife-planed orsanded or abraded to provide a bonding surface to bond the planar layerof fiber reinforced polymer.
 15. The process of claim 14 , wherein theknife-planed, sanded or abraded major surface of the wood member iscoated with the reactive hotmelt adhesive.
 16. The process of claim 14 ,wherein the altered major surface of the planar layer of fiberreinforced polymer is coated with the reactive hotmelt adhesive.
 17. Theprocess of claim 2 , wherein the edges of the composite board aremachined to trim the planar layer of fiber reinforced polymer.
 18. Theprocess of claim 2 , wherein edges of the wood member are machined toform shiplaps and crusher beads.
 19. The process of claim 2 , whereinthe reactive hotmelt adhesive is coated on both the major surface of thewood member and the altered major surface of the planar layer of fiberreinforced polymer.
 20. The process of claim 1 , wherein the hotmeltadhesive is heated to a temperature of from about 200° F. to about 350°F. before coating on one or both of the major surfaces.
 21. The processof claim 2 , wherein the hotmelt adhesive is heated to a temperature offrom about 200° F. to about 350° F. before coating on one or both of themajor surfaces
 22. The process of claim 2 , wherein the major surfacesof the wood member and the planar layer of fiber reinforced polymer tobe joined together by the hotmelt adhesive are warmed to a temperatureof from about 60° F. to about 200° F.
 23. The process of claim 1 ,wherein the reactive hotmelt adhesive is coated on one or both majorsurfaces of the wood member and the water impervious layer in an amountof about 5 to about 20 gms/sq ft of surface.
 24. The process of claim 1, wherein the reactive hotmelt adhesive is a polyurethane based hotmeltadhesive.
 25. The process of claim 2 , wherein the reactive hotmeltadhesive is a polyurethane based hotmelt adhesive.
 26. A composite woodboard produced according to the process of claim 1 .
 27. A compositewood board produced according to the process of claim 25 .
 28. A processof manufacturing a composite wood board for use with a plurality of suchcomposite wood boards in a flooring system of a vehicular trailer orcontainer, wherein each composite board comprises a unitary wood memberwith an exposed wood top surface and a bottom surface substantiallybonded to a continuous water impervious layer rendering the bottomsurface substantially non-exposed, the process comprising the steps of:providing the wood member having two opposing major surfaces; providinga water impervious layer; bonding the water impervious layer to the woodmember to produce a composite wood board by substantially continuouslycoating one or both of a major surface of the wood member and a majorsurface of the water impervious layer with an adhesive, followed byjoining of the water impervious layer to the wood member.
 29. Theprocess of claim 28 , wherein the water impervious layer comprises alayer of fiber reinforced polymer of a thermosetting or thermoplasticpolymer and reinforcing fibers.
 30. The process of claim 29 wherein atleast about 70% of the fibers of the fiber reinforced polymer extend ina direction substantially parallel to a longitudinal axis of the layerof fiber reinforced polymer.
 31. The process of claim 28 wherein atleast one of a first side surface and a second side surface of the woodmember is provided with an upper lip portion or a lower lip portion toallow the joining of two composite boards with mating profiles of sidesurfaces to form an extended planar surface of a vehicular trailer orcontainer floor.
 32. The process of claim 31 , wherein at least one ofsaid first side surface and said second side surface of the wood memberis further provided with a bead to allow the formation of a gap betweentwo composite boards placed adjacent to each other with side profiles ofeach engaging each other in a vehicular trailer or container floor. 33.The process of claim 29 , wherein said layer of fiber reinforced polymercomprises continuous rovings of glass or carbon or aramid fibers ormixtures thereof impregnated by a polymeric resin.
 34. The process ofclaim 28 , wherein said wood is a hardwood selected from the groupconsisting of ash, yellow-poplar, elm, oak, maple, birch and beech. 35.The process of claim 34 , wherein the reactive hotmelt adhesive iscoated on both the machined major surface of the wood member and thealtered major surface of the water impervious layer.
 36. A compositewood board produced according to the process of claim 28 .
 37. A processof manufacturing a composite wood board for use with a plurality of suchcomposite wood boards in a flooring system of a vehicular trailer orcontainer, wherein each composite board comprises a unitary wood memberof a plurality of wood segments and having a wood top surface and abottom surface substantially bonded to a continuous planar layer offiber reinforced polymer rendering the bottom surface substantiallynon-exposed, the process comprising the steps of: providing the woodmember with two opposing major surfaces; providing a planar layer offiber reinforced polymer having two major surfaces and a length, width,thickness and longitudinal and lateral axes, said planar layer of fiberreinforced polymer comprising a thermosetting or a thermoplastic polymerand reinforcing fibers, with at least about 70% of the fibers of saidfiber reinforced polymer extending in a direction substantially parallelto the longitudinal axis of the planar layer of fiber reinforcedpolymer; altering at least one major surface of the planar layer offiber reinforced polymer to provide a bonding surface to the planarlayer of fiber reinforced polymer; substantially aligning thelongitudinal axis of the planar layer of fiber reinforced polymer with alongitudinal axis of the wood member and substantially continuouslycoating at least one or both of a major surface of the wood member andthe at least one altered major surface of the planar layer of fiberreinforced polymer with a reactive hotmelt adhesive, followed by joiningof the planar layer of fiber reinforced polymer to the wood member andpressing of the joined surfaces together, and curing the adhesive underambient conditions to bond the planar layer of fiber reinforced polymerto the wood member to produce a composite wood board.
 38. A process ofmanufacturing a composite wood board for use with a plurality of suchcomposite wood boards in a flooring system of a vehicular trailer orcontainer, wherein each composite board comprises a unitary wood memberwith an exposed wood top surface and a bottom surface substantiallybonded to a continuous planar layer of fiber reinforced polymerrendering the bottom surface substantially non-exposed, the processcomprising the steps of: providing the wood member having two opposingmajor surfaces, first and second side surfaces, length, width, thicknessand longitudinal and transverse axes; providing a planar layer of fiberreinforced polymer having two major surfaces and a length, width,thickness and longitudinal and lateral axes, said planar layer of fiberreinforced polymer comprising a thermosetting or a thermoplastic polymerand reinforcing fibers, with at least about 70% of the fibers of saidfiber reinforced polymer extending in a direction substantially parallelto the longitudinal axis of the planar layer of fiber reinforcedpolymer; bonding the planar layer of fiber reinforced polymer to thewood member to produce a composite wood board by substantiallycontinuously coating one or both of a major surface of the wood memberand a major surface of the planar layer of fiber reinforced polymer withan adhesive, followed by joining of the planar layer of fiber reinforcedpolymer to the wood member.